Contact Stresses in Twisted Wire Cables

A procedure has been outlined for determining the stresses in twisted wire cables, without many of the restrictive assumptions imposed by previous authors. Large changes in helix angle due to loading have been considered, and the contact line loads between the individual wires of a cable have been determined for a few representative cases. A general property of the contact line load between the wires is that it increases with increasing axial cable force up to a certain point and then decreases, owing to the straightening of the cable wires (i.e., the helix angle approaching 90°). This interesting and plausible behavior, which seems to prevail for all constant values of the axial cable twisting moment, can only be predicted if the governing equations take into account the change in helix geometry due to loading.